Patent ES-8601721-A1 (ES)
Title: Use of dual-function lift gas in a FCC reactor riser.
IPC: C10G47/30
Filed: 1984-09-14
Abstract: A process for converting a charge stock comprising normally liquid hydrocarbons into lower boiling hydrocarbons in a generally vertically oriented riser conversion zone by passing an upflowing suspension consisting essentially of hot regenerated active fluid catalytic cracking catalyst in a lift gas through a lower treatment section of said vertically oriented riser conversion zone and introducing the charge stock into the upflowing suspension at a locus in the riser conversion zone downstream of the lower portion to form a mixture of catalyst, charge stock and lift gas having the catalyst relatively uniformly distributed thereghrough and thereafter reacting the charge stock with the catalyst in the upper portion of the riser conversion zone at reaction conditions sufficient to effect the desired conversion characterized in that the lift gas comprises hydrocarbons including not more than 10 mole % C3 and heavier hydrocarbons (calculated on a water-free basis) and is introduced at treatment conditions selected to selectively carbonize reaction sites on the catalyst prior to any contact with the charge stock while simultaneously accelerating the catalyst to a velocity sufficient to provide turbulent dilute flow at the point of contact with the charge stock. - (8pp) EPAB- EP-154676 B A process for converting a charge stock comprising normally liquid hydrocarbons into lower boiling hydrocarbons in a generally vertically oriented riser conversion zone by passing an upflowing suspension consisting essentially of hot regenerated active fluid catalytic cracking catalyst in a lift gas through a lower treatment section of said vertically oriented riser conversion zone and introducing the charge stock into the upflowing suspension at a locus in the riser conversion zone downstream of the lower portion to form a mixture of catalyst, charge stock and lift gas having the catalyst relatively uniformly distributed therethrough and thereafter reacting the charge stock with the catalyst in the upper portion of the riser conversion zone at reaction conditions sufficient to effect the desired conversion characterized in that the lift gas comprises hydrocarbons including not more than 10 mole % C3 and heavier hydrocarbons (calculated on a water-free basis) and is introduced at treatment conditions selected to selectively carbonize reaction sites on the catalyst prior to any contact with the charge stock while simultaneously accelerating the catalyst to a velocity sufficient to provide turbulent dilute flow at the point of contact with the charge stock. - EP-154676 B A process for converting a charge stock comprising normally liquid hydrocarbons into lower boiling hydrocarbons in a generally vertically oriented riser conversion zone by passing an upflowing suspension consisting essentially of hot regenerated active fluid catalytic cracking catalyst in a lift gas through a lower treatment section of said vertically oriented riser conversion zone and introducing the charge stock into the upflowing suspension at a locus in the riser conversion zone downstream of the lower portion to form a mixture of catalyst, charge stock and lift gas having the catalyst relatively uniformly distributed thereghrough and thereafter reacting the charge stock with the catalyst in the upper portion of the riser conversion zone at reaction conditions sufficient to effect the desired conversion characterized in that the lift gas comprises hydrocarbons including not more than 10 mole % C3 and heavier hydrocarbons (calculated on a water-free basis) and is introduced at treatment conditions selected to selectively carbonize reaction sites on the catalyst prior to any contact with the charge stock while simultaneously accelerating the catalyst to a velocity sufficient to provide turbulent dilute flow at the point of contact with the charge stock. (8pp) USAB- US4479870 A A normally liq. hydrocarbon (1) is converted by the steps (a) passing a suspension of hot regenerated active fluid cracking catalyst in a lift gas comprising hydrocarbons including no more than 10% of weight C3 and above through the lower portion (2) of a vertically oriented riser conversion zone at 1.8-12.2 metres/sec, residence time 0.5-15 sec., the catalyst: hydrocarbon wt. ratio being greater than 80 (b) introducing (1) into the suspension downstream of (2) to form a mixt. wherein the desired conversion takes place. - The catalyst is a crystalline aluminosilicate or zeolite which has been regenerated with air at 620-760 deg.C. The life gas, which in addition to hydrocarbons may contain H2, H2S, N2, CO or CO2, is obtd. from elsewhere in the cracking process. Its velocity may be adjusted by inclusion of up to 80 mole % steam. Zone (2) can be an annular space with upwards flow, with (1) flowing upwards in a central space, the two spaces and flows merging.